<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div class="app">
    <input type="file" id="file">
  </div>
  <script>
    const file = document.getElementById('file')

    function upLoad() {
      console.log('上传')
    }
    file.addEventListener('click', upLoad)

  </script>
</body>
</html>